From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 75BB236CDF8; Tue, 20 Jan 2026 06:40:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768891248; cv=none; b=BY3UpvuDuFw0AydI5jtLgIKonfbD0KkbgZHcGzE7ZGESr9dRDJIIROSlz1/An0tgY8YpJfDSRXJAqBE/1uB8gbtqzwJ7dv1eqGvFLAOX8tQZFo5enyewOt7p0/frfZYErxe9Na/wu9myfnysapwYdV/fc0PanSXt49hz/zl2DV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768891248; c=relaxed/simple; bh=+Rj7uGD9BAg2RPQZhg6lU/sk+HcT1mWI2EcyTdXtF7g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Btv9XTs6C0BlS6Nv+oD+Rzd/y5QcJVzgCJ4K6afksuDR0IykeKmPUATPBraXkw7a8t4F9pTc9rbR1Hzhg2M7o0BxQUx764bQI8oesXbX8PY0qlA20q77U1YEiW0UV/ZQVZzft4DLumwB71nsvw3dJduGjHwlomxvbRuZSo/jafk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id EDB22227AA8; Tue, 20 Jan 2026 07:40:32 +0100 (CET) Date: Tue, 20 Jan 2026 07:40:32 +0100 From: Christoph Hellwig To: Namjae Jeon Cc: Christoph Hellwig , viro@zeniv.linux.org.uk, brauner@kernel.org, tytso@mit.edu, willy@infradead.org, jack@suse.cz, djwong@kernel.org, josef@toxicpanda.com, sandeen@sandeen.net, rgoldwyn@suse.com, xiang@kernel.org, dsterba@suse.com, pali@kernel.org, ebiggers@kernel.org, neil@brown.name, amir73il@gmail.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, iamjoonsoo.kim@lge.com, cheol.lee@lge.com, jay.sim@lge.com, gunho.lee@lge.com Subject: Re: [PATCH v5 02/14] ntfs: update in-memory, on-disk structures and headers Message-ID: <20260120064032.GA3350@lst.de> References: <20260111140345.3866-1-linkinjeon@kernel.org> <20260111140345.3866-3-linkinjeon@kernel.org> <20260116082352.GB15119@lst.de> <20260119070527.GB1480@lst.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) On Tue, Jan 20, 2026 at 01:27:55PM +0900, Namjae Jeon wrote: > On Mon, Jan 19, 2026 at 4:05 PM Christoph Hellwig wrote: > > > > On Sun, Jan 18, 2026 at 01:54:06PM +0900, Namjae Jeon wrote: > > > > It seem like big_ntfs_inode is literally only used in the conversion > > > > helpers below. Are there are a lot of these "extent inode" so that > > > > not having the vfs inode for them is an actual saving? > > > Right, In NTFS, a base MFT record (represented by the base ntfs_inode) > > > requires a struct inode to interact with the VFS. However, a single > > > file can have multiple extent MFT records to store additional > > > attributes. These extent inodes are managed internally by the base > > > inode and do not need to be visible to the VFS. > > > > What are typical numbers of the extra extent inodes? If they are rare, > > you might be able to simplify the code a bit by just always allocating > > the vfs_inode even if it's not really used. > Regarding the typical numbers, in most cases, It will require zero or > only a few extra extent inodes. Okay, I will move vfs_inode to > ntfs_inode. This was just thinking out loud. If it doesn't help to significantly simplify things, don't bother.